Piece-Rate Incentive Effect vs. Worker Selection
Raising the piece rate by 10 MWK increases output quantity by 0.18 to 0.26 units sorted per day from a baseline mean of 7.35 units (p < 0.01), establishing a positive incentive effect. Controlling for actual piece rate received, reservation wage (minimum willingness to accept) exhibits a slightly negative or zero relationship with output quantity (a 10 MWK increase in minimum WTA lowers daily output by 0.20 to 0.30 units in random effects models, p < 0.05).